基于多层结构的宽阻带SIW带通滤波器

近年来，多层结构的基片集成波导(SIW)带通滤波器因其结构紧凑的优点得到研究者们的青睐，与此同时，阻带带宽窄的缺点又阻碍了滤波器的发展。为了提升滤波器的阻带性能，提出一种基于多层结构的宽阻带SIW带通滤波器。将滤波器的内外耦合窗口设置在模式的最弱电场处，从本质上抑制该模式。同时引入电磁混合耦合理论，分析特定模式的电磁分布情况，并根据HFSS软件提取的耦合系数设计耦合孔径的大小和位置，实现对特定模式的抑制。仿真结果显示可以完全抑制谐振频率低于TE₃₀₃模以内的所有高次模。实际加工并测量了该滤波器，中心频率为5.9 GHz,相对带宽为2.54%,阻带可以延伸至17.42 GHz (2.95f₀,f₀为滤波器中心频率),且带外抑制优于28 dB,仿真和测量结果显示两者吻合度较好。与其他SIW滤波器相比，该方法设计简单、带宽可调、阻带更宽，易于应用到实际的微波通信系统中，具有潜在的应用价值。     

SIR实现的新型毫米波UWB滤波器

提出了一个用阶跃阻抗谐振器(SIR)实现的毫米波超宽带(UWB)滤波器。滤波器的基本单元是一个由半波长微带线谐振器和SIR组成的三模谐振器。该谐振器采用SIR结构,从而达到阻带宽、结构紧凑,且能很好地改善带外抑制。为了进一步改善阻带特性,该三模谐振器与半波长谐振器平行耦合形成新型的滤波器。该滤波器有多个传输极点和传输零点,形成陡峭的通带边缘特性和很宽的阻带。实验测得滤波器的-3 dB相对带宽为35.7%,通带内的插入损耗约为-1.7 dB。插入损耗低于-17 dB的高频端阻带可到76 GHz。滤波器的仿真结果和测试结果基本吻合。     

低频大带宽声表面波滤波器

介绍了一种低频大带宽声表面波滤波器(SAWF)的设计方法，并介绍了最新研制的滤波器的性能。其中心频率16．28MHz，通带波动1．0dB，插入衰耗23dB，阻带抑制达40dB。     

一种基于正方环形谐振器的新型宽带带通滤波器

本文设计了一种紧凑型、宽通带、宽阻带的微带带通滤波器。该滤波器的设计是基于带有两个开路调节支节的正方谐振环。基于紧凑性的考虑,改变了传统方环谐振滤波器的馈电点和开路调节支节的位置,以便对谐振环进行折叠处理。这种改变并不影响谐振环的奇偶模特性。在输入和输出端口,通过两个叉指耦合结构对滤波器进行馈电,这种馈电方式增加了滤波器阻带的带宽和抑制度。滤波器的中心频率为4GHz,相对带宽为45％,通带内的回波损耗小于-12dB,群时延小于0．8ns,1-2．9GHz阻带抑制度大于12dB,5．3～7GHz阻带抑制度大于18dB。     

半模基片集成波导带通滤波器的设计

给出了一种新型半模基片集成波导（HMSIW）带通滤波器的设计和实验方案。该设计利用了半模基片集成波导的高通性质与周期性缝隙的带阻性质来产生带通滤波器的效果。设计的滤波器的中心频率在8GHz,带宽在12．5％左右,通带内插入损耗在1dB以下,回波损耗在-15dB以下,同时具有一定的带外抑制和良好的通带和阻带特性。文章最后用Ansoft HFSS软件进行了仿真实验。     

恒定阻带抑制矩阵滤波器性能分析

在任意传感器阵型恒定阻带抑制矩阵滤波器设计的基础上,全面讨论了影响恒定阻带抑制矩阵滤波器性能的因素。矩阵滤波器设计问题可转化为二阶锥规划问题,通过求解二阶锥规划及重排可得所需的矩阵滤波器。分析并得出阻带响应、通带位置、通带带宽及阵元数等因素变化对矩阵滤波器性能的影响,为矩阵滤波器的设计和应用提供了依据。     

滤波器耦合槽直径对其性能的影响仿真

采用高频结构模拟软件模拟1／4λ同轴型带通微波陶瓷滤波器结构,讨论了耦合槽直径对滤波器的性能如带宽、插损、带内波动、阻带抑制等的影响。结果表明,随着耦合槽直径的增大,滤波器中心频率、插入损耗和阻带抑制减小,3dB带宽增大。讨论结果表明,可通过调整滤波器耦合槽直径的大小,得到理想性能的介质滤波器。     

基于双方环结构的超宽带平衡滤波器设计

平衡滤波器因具有卓越的抗噪声及抗电磁干扰能力而在繁杂频谱环境下的低噪通信系统中显得至关重要。该文提出了一款具有共模抑制特性的平衡滤波器,通过差共模理论结合导纳矩阵及传输矩阵完成了分析设计。该滤波器中心频率为1．4 GHz,相对带宽可达74．3%,覆盖2G、GPRS、3G及4G LTE频段。同时该滤波器的边带具有两对传输零点,故其具有理想的边带滚降速度及边带抑制水平。滤波器全差模通频带内共模信号抑制水平均优于10 dB,差模阻带抑制优于20 dB,电路尺寸仅为0．17λ_g×0．17λ_g。     

一种新型介质栅波导滤波特性的研究

提出了一种新型介质栅波导阻带滤波结构,并采用多模网络与严格模匹配相结合的方法对该阻带滤波特性进行了仔细分析,给出了主模TM模的Brillouin图及滤波结构的归一化中心频率、阻带的宽度和带内最大衰减等特性和结构参数的关系.与传统的介质栅滤波器相比,新滤波器结构不仅具有金属损耗小的优点,而且其阻带带宽和带内衰减都要比传统介质栅滤波器的大得多.文中所给出的计算结果对设计该新型带阻滤波结构有指导意义.     

基于128°YX-LiNbO3压电材料的DMS滤波器设计

设计了一种基于128°YX-LiNbO₃压电材料的双模耦合声表面波(DMS)滤波器。采用耦合模(COM)模型进行理论分析,得到DMS滤波器的二维器件模型,再采用COMSOL进行二维器件仿真分析,得到单级DMS滤波器。为了消除该DMS滤波器在其低端近阻带附近出现的肩峰,该文提出将DMS滤波器表面覆盖一层SiO₂薄膜,形成温度补偿结构,从而解决低端近阻带附近的肩峰。结果表明,设计的DMS滤波器的中心频率为891.0 MHz,最小插入损耗为-1.29 dB,1 dB带宽为34.0 MHz,相对带宽为3.8%,矩形系数为2.94,带外抑制约为-20 dB。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks